Possible Causes
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED HIGH
EVAPORATOR TEMPERATURE SENSOR
EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN
SENSOR GROUND CIRCUIT OPEN
A/C - HEATER CONTROL MODULE